• Journal of Korean Society for Atmospheric Environment
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• v.15 no.1
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• pp.23-32
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• 1999

Deposition is one of the important removal mechanisms for the ambient aerosol, and it also leads to adverse environmental and economic impacts. The purpose of this study was to investigate chemical compositions and spatial distributions of fall-out aerosols. A total number of 340 samples were collected at 35 sampling sites in Suwon area from January to November, 1996. Twelve inorganic elements (Al, Ba, Cd, Cr, K, Pb, Sb, Zn, Cu, Fe, Ni, and V) and eight ionic components ($F^-$, Cl, $NO_3^-$, $SO_4^{2-}$, $Na^+$, $NH_4^+$, $Mg^{2+}$, and $Ca^{2+}$) were analyzed by AAS and IC, respectively. The monthly variation showed that the flux of fall-out particles was increased in the spring season(March, April, and May) and decreased from August to October. Arithmetic mean flux of fall-out particles was 176.8 kg/$ extrm{km}^2$/day during the study period. The fluxes of each chemical species were $SO_4^{2-}$ 12.414, $Ca^{2+}$ 7.369, $NO_3^-$ 5.812, $Cl^-$ 3.566, $NH_4^+$ 3.176, Fe 3.107 kg/$\textrm{km}^2$/day, and so on. By using a kriging analysis, spatial distribution pattern of those fluxes was intensively studied. Total fluxes estimated in Suwon city were 8424.72t/y of fall-out particles, 519.27t/y of $SO_4^{2-}$, 336.79t/y of $Ca^{2+}$,267.34 t/y of $NO_3^+$, 155.36t/y of $Cl^-$, 147.79t/y of Fe.

• Journal of Navigation and Port Research
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• v.29 no.5 s.101
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• pp.431-437
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• 2005

In korea, Freight generation models developed in korea were estimated by spatial unit method which predict freight flow by traffic zone. But it is difficult to predict freight generation using these models, because there are the difference of the totality method of sampling data on freight volume and the variability of the variables by these models on each case study, This study developed new estimation model to predict freight flow which is generated from each company using the characteristics of each company such as the freight outbound & inbound volume, the number of employee, sales, gross area, land area. This model is simpler than the that of spatial unit and can apply to the other region. The subjects of study were companies in metropolitan area and types of model were exponential regression models. The adequate explanatory variable in the models were sales. this study have a uniqueness apply micro research method to estimate freight generation not use spatial unit method but use flow unit method by each company unit.

• Korean Journal of Remote Sensing
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• v.25 no.4
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• pp.321-338
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• 2009

The objective of this paper is to compare spatial prediction capabilities of univariate kriging algorithms for generating GIS-based thematic maps from ground survey data with asymmetric distributions. Four univariate kriging algorithms including traditional ordinary kriging, three non-linear transform-based kriging algorithms such as log-normal kriging, multi-Gaussian kriging and indicator kriging are applied for spatial interpolation of geochemical As and Pb elements. Cross validation based on a leave-one-out approach is applied and then prediction errors are computed. The impact of the sampling density of the ground survey data on the prediction errors are also investigated. Through the case study, indicator kriging showed the smallest prediction errors and superior prediction capabilities of very low and very high values. Other non-linear transform based kriging algorithms yielded better prediction capabilities than traditional ordinary kriging. Log-normal kriging which has been widely applied, however, produced biased estimation results (overall, overestimation). It is expected that such quantitative comparison results would be effectively used for the selection of an optimal kriging algorithm for spatial interpolation of ground survey data with asymmetric distributions.

• Korean journal of applied entomology
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• v.42 no.1
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• pp.29-34
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• 2003

Dispersion pattern for adult citrus red mite (CRM), Panonychus citri (McGregor) using by Taylor's power law (TPL) and Iwao's patchiness regression (IPR) was determined to develop a monitoring method on citrus orchards, on Jeju, in Autumn season, during 2001 and 2002.CRM population was sampled by collecting leaves and fruits. The relationships of CRM adults between leaf and fruit were analyzed by different season. The regression equation for CRM adults between leaf (X) and fruit (Y) was ln(Y+1) : 1.029 ln(X+1) ( $r^2$ : 0.80). The density of CRM was higher on fruit than on leaf according to fruit maturing level. TPL provided better description of mean-variance relation-ship for the dispersion indices compared to IPR. Slopes and intercepts of TPL from leaf and fruit samples did not differ between sample units and surveyed years. Fixed-precision levels (D) of a sequential sampling plan were developed using Taylor's power law parameters generated from adults of CRM in leaf sample. Sequential sampling plans for adults of CRM were developed for decision making CRM population level based on the different action threshold levels (2.0,2.5 and 3.0 mites per leaf) with 0.25 precision. The maximum number of trees and required number of trees sampled on fixed sample size plan on 2.0,2.5 and 3.0 thresholds with 0.25 precision level were 19, 16 and 15 and their critical values T$_{critical}$ at were 554,609 and 659, respectively. were 554,609 and 659, respectively.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2010.09a
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• pp.119-125
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• 2010

본 연구에서는 항공 라이다 데이터로부터 지표의 유형을 분류하는 과정에서 필요한 처리시간을 감소시켜 보다 효율적인 지형 분류가 가능하도록 타일 단위의 샘플링을 이용한 지형 분류 기법을 제안하였다. 또한 실험을 통하여 샘플링 정도에 따라 정확도와 시간효율을 비교분석하여 최적의 샘플링 정도를 제시하였다. 본 연구에서 제안한 타일 단위의 샘플링을 이용한 지형 분류기법을 이용해 자연재해내 도시 구조 변화 등의 지형정보의 변화를 탐지하기 위한 모니터링 목적으로 활용할 경우에 지형분류의 정확도 손실을 최소화하면서 빠른 처리가 가능하기 때문에 실시간 서비스가 가능해 질 수 있다.

• Environmental Analysis Health and Toxicology
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• v.16 no.4
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• pp.161-170
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• 2001

In aqueous ecosystems, the level of toxicity is highly responsive dependant to multiple variables, including rainfall, sunlight, pH, adhesion, etc. Because Korea has particularly distinct wet and dry seasons, the toxicity of pollutants in rivers or streams is dependant on the sampling season and time. In order to examine the effects of rainfall on toxicity, sediment samples were collected from five sites along the Keumho river. It was found that Microtox toxicity levels were generally higher during the dry season than the wet season. It indicated that river pollutants are carried off more quickly by the water during the wet season. As a result, it was recommended that the point sources of pollutants of the Keumho river would be placed between KH3 (Paldalgyo) and KH4(Keumhogyo), KH4(Keumhogyo) and KH5(Dasa).

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.1053-1054
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• 2008

This paper presents the mobile robot initial velocity estimation using spatial/temporal information from passive RFID system. A mobile robot is traveling along a sequence of line segments, each at a constant velocity, and the number of passive tags sensed at every sampling instant is at most one. To simplify the problem, a mobile robot is commanded to traverse two passive tags with steering angle unchanged. The 6th order polynomial equation for the mobile robot initial velocity estimation is obtained, along with some discussion on resolving the multiplicity of solutions.

• Journal of the Korean Society of Visualization
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• v.3 no.1
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• pp.71-77
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• 2005

Information on temporal evolution of whole velocity fields are essential for physical understanding of a complicated turbulent flow. Due to advances of high-speed imaging technique, laser and electronics, high-speed digital cameras and high-repetition pulse lasers are commercially available in nowadays. A dynamic PIV system that can measure consecutive instantaneous velocity field with 1K$\times$ 1K pixels resolution at 1 fps was developed. It consists of a high-speed CMOS camera and a high-repetition Nd:YLF pulse laser. Theoretically, it can capture velocity fields at 20 fps with a reduced spatial resolution. In order to validate its performance, the dynamic PIV system was applied to a turbulent jet of which Reynolds number is about 3000. The particle images of 1024$\times$512 pixels were captured at a sampling rate of 4 KHz. The dynamic PIV system measured successfully the temporal evolution of instantaneous velocity fields of the turbulent jet, from which spectral analysis of turbulent structure was also feasible.

• Journal of Environmental Impact Assessment
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• v.23 no.3
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• pp.220-226
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• 2014

This study investigated temporal-spatial and variations in Geostationary Ocean Color Imager (GOCI) products of parameters total suspended solids (TSS) and chlorophyll-a in the North Marine Areas of East China Sea.GOCI data were collected daily from February 2012 to December 2012. The higher chlorophyll-a values were observed during the investigation period. The relatively large increase in TSS and chlorophyll-a at the sampling stations coupled with typhoon events during the summer rainy period. The abnormal chlorophyll-a concentration was mainly driven by meteorological factors such as typhoon and rainfall in the coastal areas of Jeju and the North Marine Areas of East China Sea. The abnormal high chlorophyll-a concentration at the majority of the coastal stations indicate eutrophication of coastal waters, especially Red tide. The events such as eutrophication and abnormal high chlorophyll-a concentration may potentially influence outbreak of Red Tide, detected with GOCI parameters.

• Journal of Environmental Science International
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• v.23 no.12
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• pp.2071-2082
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• 2014

In this study, the environmental consciousness of Daegu citizen on conservation planning considering the regional characteristics was investigated. Data were collected throughout a survey and 1400 people were selected using a stratified sampling method based on populations of Daegu administration district. Results wee followings; First, the levels of environmental consciousness were different dependent on districts' characteristics. Second, poor awareness on Daegu Agenda 21 (Clear and Green Daegu 21) were shown. Daegu Agenda 21 is the action plan for the sustainable environmental conservation activities of the City of Daegu. Third, waste was the most serious environmental problems of Daegu, air quality was second worst, and third was river water quality from the survey, but differentiated awareness was shown dependent on regional spatial factors and pollution emission factors. Last, a public environmental education was the most important issue to make invigorations and progress for future environmental policy.